The Bryn-Marsli Enclosure is defined by two curving, concentric ditches visible as cropmarks to the south of the farm, possibly linked in an arc at the east end and thus comprising a single, elongated reverse-C ditch. It would appear to be unrelated to the present field boundaries and is partially obscured by modern farm buildings. It may therefore represent a fragment of a prehistoric defended enclosure. It was discovered during RCAHMW aerial reconnaissance on 27 July 2005.

T. Driver, RCAHMW, 25 June 2007.